WS here. I have a slightly different take on this, so I hope you don't mind another opinion.
Have you ever read any Brene Brown? In her book Rising Strong, she describes an incident at their lake house. The two of them went swimming together, and as they are swimming along, Brene starts to feel feelings of closeness with her husband, and tries to engage him in conversation, hoping to connect. Her husband keeps responding with polite but curt replies, and then swims away. Brene starts to feel as if something is wrong. Why does he keep swimming away and not engaging? Does he not love her anymore? Does she look fat in her swimsuit? What's wrong with him? Long story short, after they get back to shore and she shares her feelings with him, he reponds that had nightmares the night before about them and the kids drowning in the lake, and he was having a massive panic attack as they swam. His shortness with her had nothing to so with the stories she was telling herself, not even a little. He had one story going on in his head, and she had another, in though they were both in the same place at the same time doing the same thing.
My wife and I just had a similar experience this past week. I'll skip the details to keep this short, however the upshot of the story was that I had completely misread a situation (mia culpa), and like Brene, interpreted the situation from my own point of view, without really understand what had actually occurred. But it took us a while of talking before I realized that we were playing a game of "who's on first". Once I understood that "Who" was a person, not a question, it all fell into place.
Anyway, my point is, when people argue about the dishes piling up in the sink, it is rarely the dishes that are the problem. It's the feeling of not being respected, cared for, and thought about, that makes us so angry.
It sounds to me like there is something else in this mix that hasn't been discovered yet. Your wife overreacted to this event, yes, but the mere fact that she blew up so badly is a sign (to me anyway) that something deeper is going on. In fact, if I had to guess, it sounds like something triggered her. She got angry at you (and I'm sorry you had to bear that, you really didn't do anything wrong, and it's a lot to ask of someone to be understanding of the spouse that cheated on them) but my guess is that her anger is misdirected. She might be angry at herself for not getting things on the schedule like she should have. Or maybe she was under a lot of pressure about this event and hadn't really shared that with you? Or maybe it triggers her to remember a time in her life when she felt unseen, unheard or uncared for by someone else (A parent maybe? A family member) and she reacted towards you, but the response was really an echo of something long since passed.
If you happen to feel that it is still worth the effort, than I would suggest taking a walk together, and discussing what was going on in her head that day, and why she blew up over a simple scheduling mistake. Don't allow it to go into a finger-pointing exercise. Focus instead on "what were you feeling" and "why do you think you felt that way" and "is it bringing anything else up for you?". Arguments such as these can be opportunities for growth and closeness sometimes, if we want them to be. Make sure to share your feelings as well. Make it clear that this was a trigger for you too, as it reminds you of how you felt when she cheated on you, and that R is not going to work unless she learns to disengage and discuss her feelings.
She can't open up to you until she learns to open up to herself first. Sometimes we get so used to the walls we've put up that we don't even see them anymore, so it can be helpful for others to point them out.
I realize you don't owe her anything, and if you are truly "done" as you said, then feel free to ignore my suggestions. I just wanted to offer another viewpoint in case it is of any value to you.